Open Proxy Servers
Table of Contents
Companies and ISPs often use caching in proxy servers to reduce the
load on their networks. These proxy servers are often configured to proxy
any port, with little regard to security. If nothing is blocking connections
from the outside, it is possible to detect the vulnerable server by scanning
the ports of a range of IP addresses.
Often, a proxy server is open because it has not been configured properly.
Most of open proxy servers are not supposed to be public. The person that
configured the server was not aware of the potential problems and security
risks. It is very common to for a novice administrator to set up a proxy
with access rights that allow anyone to connect. To close a proxy server
it is necessary to force users to connect from one IP address or a range
of IP addresses. An alternative is to require users to use a user name
'Honey Pots' or 'Honey Proxies'
Everything that is done on or through the open proxy server can be logged
and traced. A honey pot is an open proxy server intentionally deployed
by security professionals to lure hackers and track their every move.
A honey pot can also be installed by a hacker. A hacker can put a proxy
server up on his, or a victim's computer and wait for a scanner to find
it. Sending spam e-mail trough a honey pot proxy exposes the sender's
activity. When a spammer uses the proxy to send bulk email, it is possible
to collect the content of the spam and report the spammer to his ISP.
When you use an open proxy server, your computer is making a direct
connection to another computer. You do not know who is in control of the
remote computer. If you are using proxy servers from open proxy lists,
you could be trusting your email messages, passwords or other sensitive
information to a person running the server. Someone can be watching the
unencrypted information you are transferring over the network.
Lists of Open Proxies
To find available proxy servers, it is not necessary to scan a range
of IP addresses. There are many lists available that are frequently updated.
The servers on those lists are usually on a list one day and gone the
next. When the network bandwidth drastically increases, the open proxy
problem is easily found and resolved.
There are programs available on the Internet that automatically redirect
your traffic through different proxies. Some of these programs chain proxies
together for additional protection. One of them is SocksChain. See the
SocksChain Application topic
for more information.
- Firewalls and Proxies Explained
- Open Proxy Servers